The invention relates, generally, to laser surgery and, more particularly, to a device for supplying pressurized fluid to a flexible fiber optic guide.
Surgical lasers are typically comprised of a main chassis for generating the laser energy coupled through a flexible fiber optic guide to the surgical instrument. The flexible fiber optic guide consists of an optic fiber through which the laser energy travels and a flexible sleeve arranged coaxially over the optic fiber for the length thereof. The space between the optic fiber and the sleeve acts as an annular conduit for delivering fluid through the guide to the surgical instrument.
The fluid is used to keep debris, generated during the operation procedure, away from the optic fiber and surgical instrument. The fluid also acts as a coolant and is especially beneficial in this regard during so called "contact surgery", where the surgical laser instrument actually contacts the tissue.
The fluid, in these laser systems, flows in an open system from the source through the fiber optic guide to the surgical tip where it is discharged at the operation situs. Because the fluid is discharged at the operation situs, it is critical that the fluid, especially liquid, remains in a sterile condition throughout the supply operation. To insure the sterility of the fluid, the sterile fluid source and the fiber optic guide are made disposable and are replaced after each operation procedure.
The known prior art systems achieve this result by connecting a standard I.V. type bottle directly to the fiber optic guide. The bottle is elevated such that gravitational force propels the liquid through the system. While this rudimentary system maintains the sterility of the liquid, the use of gravity to propel the liquid makes it very difficult to select or regulate the flow rate of the liquid. Of course, variances in the flow rate of the fluid can have serious repercussions in the type of sensitive surgical operations in which these laser surgical instruments are used. Moreover, in order to sterilize the flow rate indicators of the prior art they must be dismantled. Thus, because these prior art devices must be sterilized before each use, their upkeep and maintenance is very expensive.
An example of a known type of cassette for a surgical system is disclosed in U.S. Pat. No. 4,493,695 issued to Cook. Cook's apparatus is designed to simplify the "hook up" of the various wires and plugs normally associated with a microsurgical suction system by isolating the various connections in a single disposable cassette. However, this apparatus does not provide a controllable pumping means for varying the flow rate of the fluid. Cook merely uses a "gate" for restricting the liquid path. Moreover, Cook does not disclose a gas delivery system that is controllable in conjunction with a liquid delivery system.